Ice making device

ABSTRACT

An ice making device may include an ice making unit having an ice tray and a heater; and a drive unit connected with the ice making unit. The drive unit may include a drive source, a cam body driven by the drive source, a leaf switch in which a leaf contact piece is displaced by a cam face of the cam body to perform “ON” or “OFF” operation, and a case body. The case body is provided with a first partition wall which partitions the inside of the case body into a first space and a second space, and the leaf switch and at least the cam face of the cam body is disposed in the second space. The first space may be preferably located on an ice making unit side and the first space is interposed between the second space and the ice making unit.

CROSS REFERENCE TO RELATED APPLICATION

The present invention claims priority under 35 U.S.C. §119 to JapaneseApplication No. 2006-236889 filed Aug. 31, 2006, which is incorporatedherein by reference.

FIELD OF THE INVENTION

An embodiment of the present invention may relate to an ice makingdevice in which a drive unit is connected with an ice making unitprovided with an ice tray and a heater.

BACKGROUND OF THE INVENTION

An ice making device is structured such that a raking member isrotationally driven by a drive unit to discharge ice pieces from an icetray. In this case, when an ice adhering force between the ice tray andthe ice pieces is large, the ice pieces cannot be discharged. Therefore,the ice making unit is structured such that a heater is provided nearthe ice tray (for example, see Japanese Patent Laid-Open No.2003-143808).

In the ice making device as described above, in order to control atiming for discharging ice pieces from the ice tray, the drive unit isconnected with an ice making unit and a switch is disposed within thedrive unit. However, the ice making device is disposed within arefrigerator or a freezer. Therefore, a large temperature variationoccurs at a circumference of the ice making device whenever a door isopened and closed and thus dew formation may occur in the drive unit tocause freezing of the switch to occur malfunction. Further, when icepieces are to be discharged from the ice tray, warming of the ice traywith the heater is performed. Therefore, dew formation may occur in thedrive unit due to a temperature variation based on the warming to causefreezing of the switch to occur malfunction. Accordingly, a micro-switchor a contact-less sensor is required to use as the switch in the driveunit in the ice making device.

However, a micro-switch and a contact-less sensor are expensive and thuscost of the ice making device increases.

SUMMARY OF THE INVENTION

In view of the problems described above, an embodiment of the presentinvention may advantageously provide an ice making device which iscapable of preventing occurrence of malfunction due to freezing evenwhen a leaf switch is used as a switch mechanism.

Thus, according to an embodiment of the present invention, there may beprovided an ice making device including an ice making unit having an icetray and a heater for heating the ice tray, and a drive unit connectedwith the ice making unit. The drive unit includes a drive source, a cambody which is driven by the drive source, a leaf switch in which a leafcontact piece is displaced by a cam face of the cam body to perform “ON”and “OFF” operation, and a case body which accommodates the drivesource, the cam body and the leaf switch in an inside of the case body.The case body is provided with a first partition wall which partitionsthe inside of the case body into a first space and a second space, andthe leaf switch and at least the cam face of the cam body is disposed inthe second space.

In accordance with an embodiment of the present invention, a leaf switchin which a leaf contact piece is displaced by a cam face of the cam bodyto perform “ON” and “OFF” operation is used as a switch and thus cost isinexpensive. Further, since the cam body and the leaf switch areaccommodated within the case body, even when temperature variation isoccurred in the outside of the case body, dew formation does not easilyoccur in the inside of the case body. Therefore, the leaf switch can beprevented from freezing. In addition, the inside of the case body ispartitioned into the first space and the second space by the firstpartition wall, and the leaf switch and at least the cam face of the cambody is disposed in the second space. In other words, the leaf switchand at least the cam face of the cam body is disposed in a space whosetemperature variation is smaller of the first space and the secondspace. Therefore, even when temperature variation is occurred in theoutside of the case body due to opening/closing of a door of arefrigerator or a freezer or due to heating with the heater on the sideof the ice making unit, dew formation in the space where the leaf switchand at least the cam face of the cam body are disposed can be reduced.Accordingly, the leaf switch can be prevented from freezing to causemalfunction to occur.

In accordance with an embodiment of the present invention, the firstspace is located on an ice making unit side and the first space isinterposed between the second space and the ice making unit. Accordingto the structure described above, even when temperature variation isoccurred in the outside of the case body due to heating with the heateron the side of the ice making unit, temperature variation in the spacewhere the leaf switch and at least the cam face of the cam body aredisposed is small.

Specifically, the case body includes a base plate as the first partitionwall which is disposed within the case body, one side portion of the cambody which is driven by a motor as the drive source is disposed in thefirst space, the other side portion of the cam body is protruded in thesecond space through a through hole which is formed in the base plate,the one side portion of the cam body is formed with an outer teeth gearwhich is rotationally driven by the motor and a cylindrical part forrotating a raking member for raking out ice pieces manufactured in theice tray of the ice making unit, and the other side portion of the cambody disposed in the second space is formed with the cam face forperforming “ON” and “OFF” operations with the leaf switch. In this case,it is preferable that the rotary cam body is rotatably fitted into thethrough hole so as to close the through hole so that the first space andthe second space are partitioned off each other.

In accordance with an embodiment of the present invention, a secondpartition wall is formed in the case body for partitioning the secondspace into a first small space and a second small space, and the leafswitch and at least the cam face of the cam body is disposed in thefirst small space. When the leaf switch and at least the cam face of thecam body is disposed in one of the spaces of the first space and thesecond space whose temperature variation is smaller than the other, evenwhen temperature variation is occurred in the outside of the case body,the leaf switch can be prevented from freezing to cause malfunction tooccur.

In accordance with an embodiment of the present invention, the firstsmall space is formed at a position apart from the heater in comparisonwith the second small space. According to the structure as describedabove, even when temperature variation is occurred in the outside of thecase body due to heating with the heater on the side of the ice makingunit, temperature variation in the first small space where the leafswitch and at least the cam face of the cam body are disposed becomessmall. Specifically, the ice tray and the heater for heating the icetray are disposed on a side of the second small space.

In accordance with an embodiment of the present invention, the secondpartition wall includes a facing portion which faces an outer wall ofthe case body to doubly surround the first small space. According to thestructure as described above, even when temperature variation isoccurred in the outside of the case body, temperature variation in thefirst small space where the leaf switch and at least the cam face of thecam body are disposed becomes small.

In accordance with an embodiment of the present invention, the drivesource is disposed in the first space, and a power supply member for thedrive source is penetrated through a slit which is formed in the firstpartition wall. According to the structure as described above, even whenthe first partition wall is formed with the penetration portion,temperature variation in the second space becomes small.

In accordance with an embodiment of the present invention, atransmission mechanism for transmitting a driving force of the drivesource to the ice making unit at a time of discharging ice pieces fromthe ice tray is disposed in the first space. The transmission mechanismis subjected to less effect of freezing than a switch and the like.Therefore, when the transmission mechanism is disposed within the firstspace, the inside of the case body is effectively utilized and, even inthis case, malfunction due to freezing can be prevented.

Other features and advantages of the invention will be apparent from thefollowing detailed description, taken in conjunction with theaccompanying drawings that illustrate, by way of example, variousfeatures of embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described, by way of example only, withreference to the accompanying drawings which are meant to be exemplary,not limiting, and wherein like elements are numbered alike in severalFigures, in which:

FIG. 1 is a perspective view showing an ice making device in accordancewith an embodiment of the present invention.

FIG. 2(A) is a perspective view showing a raking member, FIG. 2(B) is aperspective view showing an ice tray, and FIG. 2(C) is a perspectiveview showing a guide member, which are used in the ice making deviceshown in FIG. 1.

FIG. 3(A) is a front view showing the ice making device shown in FIG. 1,FIG. 3(B) is a cross-sectional view showing a state where the rakingmember in the ice making device is located at a home position, and FIG.3(C) is a cross-sectional view showing a state where the raking memberhas turned from the home position.

FIGS. 4(A) through 4(D) are explanatory circuit diagrams showing aschematic electrical structure of a drive unit of the ice making deviceshown in FIG. 1.

FIGS. 5(A) through 5(D) are explanatory circuit diagrams showing theschematic electrical structure of the drive unit of the ice makingdevice shown in FIG. 1.

FIG. 6 is a timing chart showing an operation of the ice making deviceshown in FIG. 1.

FIG. 7 is an explanatory view showing an inner case which is used in thedrive unit and structural members disposed within the inner case in theice making device shown in FIG. 1.

FIG. 8(A) is a side view showing a rotary cam body which is used in theice making device shown in FIG. 1 and FIG. 8(B) is an explanatoryperspective view showing three leaf contact pieces which structure amain switch.

FIG. 9(A) is a plan view showing a torque limiter which is provided inthe ice making device in accordance with an embodiment of the presentinvention and FIG. 9(B) is its exploded perspective view.

FIG. 10 is an explanatory view showing a base plate used in the driveunit and structural members which are disposed on an outer case side ofthe base plate in the ice making device shown in FIG. 1.

FIGS. 11(A) through 11(F) are explanatory views showing operations ofthe drive unit structured in the ice making device shown in FIG. 1.

FIG. 12 is an explanatory view showing an outer case used in the icemaking device shown in FIG. 1 which is viewed from an outer side.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An ice making device to which the present invention is applied will bedescribed below with reference to the accompanying drawings.

FIG. 1 is a perspective view showing an ice making device in accordancewith an embodiment of the present invention. FIG. 2(A) is a perspectiveview showing a raking member, FIG. 2(B) is a perspective view showing anice tray, and FIG. 2(C) is a perspective view showing a guide member,which are used in the ice making device shown in FIG. 1. FIG. 3(A) is afront view showing the ice making device shown in FIG. 1, FIG. 3(B) is across-sectional view showing a state where the raking member in the icemaking device is located at a home position, and FIG. 3(C) is across-sectional view showing a state where the raking member has turnedfrom the home position.

In FIG. 1, FIGS. 2(A) through 2(C) and FIGS. 3(A) through 3(C), an icemaking device 1 in accordance with an embodiment is a device in whichice pieces are successively manufactured within a refrigerator or afreezer and manufactured ice pieces are automatically discharged to anice storage part 1 a which is disposed on a lower side. The ice makingdevice 1 includes an ice making unit 2 for manufacturing ice pieces anda drive unit 3 (drive control part) for controlling a raking operationand the like of the ice pieces. An ice detecting lever 60 formed in aroughly L-shape is extended toward the lower ice storage part 1 a fromthe drive unit 3. The ice making unit 2 includes an ice tray 21, awater-supply part 22 disposed on a side (rear side) of the ice tray 21for supplying the ice tray 21 with water, a raking member 23 for rakingout the ice pieces manufactured in the ice tray 21, a guide member 24for guiding the ice pieces which has been raked out by the raking member23 to the ice storage part 1 a located downward of the ice tray 21, andan end plate 25 structuring a right side face of the ice tray 21.

The ice tray 21 is made of aluminum on which surface treatment such ascoating or alumite treatment is performed. A plurality of ice makinggrooves 215 (recessed part for ice making) is dividedly formed on anupper face of the ice tray 21 by partition plates 218. Water suppliedfrom the water-supply part 22 is respectively stored in the plurality ofice making grooves 215 to be frozen up. A heater 26 for heating a bottomface of the ice tray 21 when the ice pieces are to be discharged fromthe ice tray 21 is disposed on a bottom face of the ice tray 21. Theheater 26 is integrated with the ice tray 21 by caulking or the like.Two terminal parts 262 made of rubber for the heater 26 are protrudedfrom a left side face part of the ice tray 21 and a terminal 261 isprotruded from a tip end face of the respective two terminal parts 262.A temperature detecting part 219 is formed in an area between the twoterminal parts 262 of the ice tray 21 and a thermostat is abutted withthe temperature detecting part 219 to monitor temperature of the icetray 21.

The water-supply part 22 is disposed on an opposite side (rear side) tothe side where the ice pieces are discharged (front side) with respectto the ice tray 21 and is provided with a water-supply port 221 whichopens in a rear wall of the ice tray 21. Water is supplied from a hose228 to the water-supply part 22 and a water-supply valve 220 is providedat a midway position of the hose as schematically shown in FIG. 3(B).

The raking member 23 is provided with a rotation shaft 231 which islaterally extended at an upper position of the ice tray 21 and aplurality of raking parts 232 which are protruded from the rotationshaft 231 in a claw-like shape in the same direction. The respectiveraking parts 232 are provided so as to correspond to the respective icemaking grooves 215. A right side end part of the rotation shaft 231 isrotatably supported by a cutout part 211 which is formed at an edge partof a right side face part 217 of the ice tray 21 and is rotatablysupported by a shaft hole 251 formed in the end plate 25. Further, aflange part 239 formed at the right side end part of the rotation shaft231 is abutted with an inner side face of the end plate 25 and thusmovement of the rotation shaft 231 toward the right side is restricted.On the other hand, the other end of the rotation shaft 231 is formed ina D-cut (D-shaped) portion 230 and, as shown in FIG. 3(A), the D-cutportion 230 is connected with a rotary cam body 55 (cam body) disposedwithin the drive unit 3.

In accordance with an embodiment, a position of the raking part 232shown in FIG. 3(B) is set to be a home position. In the home position,the raking parts 232 are set in a state that the raking parts 232 areinclined on an opposite side to the water-supply port 221 with respectto the rotation shaft 231. From this state, the rotation shaft 231 isturned in a direction shown by the arrow “A” to reach to a positionshown in FIG. 3(C). During this movement, the raking parts 232 cause icepieces in the ice making grooves 215 to move up from the ice tray 21.The ice pieces moved up from the ice tray 21 by the raking parts 232slide on the raking parts 232 and an upper face of the guide member 24to fall to the ice storage part 1 a from a front side of the ice tray21. In this case, the ice pieces moved up from the ice tray 21 may notfall to the ice storage part 1 a by only the raking parts 232 which havereached to the state shown in FIG. 3(C) from the state shown in FIG.3(B). However, the ice pieces in the ice tray 21 has completely fallento the ice storage part 1 a before the raking parts 232 are returned tothe home position shown in FIG. 3(B).

FIGS. 4(A) through 4(D) and FIGS. 5(A) through 5(D) are explanatorycircuit diagrams showing a schematic electrical structure of a driveunit of the ice making device shown in FIG. 1. FIG. 6 is a timing chartshowing an operation of the ice making device shown in FIG. 1.

A mechanical structure of a drive unit 3 of the ice making device 1 inaccordance with an embodiment will be described in detail below withreference to FIG. 7, FIG. 8(A) and the like. The drive unit 3 of the icemaking device 1 in this embodiment includes, as shown in FIG. 4(A), athermostat 91 for monitoring temperature of the ice tray 21, a motor 5for driving the rotation shaft 231, a main switch 72 for performingopen/close operation in conjunction with rotational operation of arotary cam body 55 shown in FIG. 3(A), a water-supply switch 73 forcontrolling the water-supply valve 220 in conjunction with therotational operation of the rotary cam body 55, an ice detecting switch71 for monitoring whether the ice storage part 1 a is in a shortagestate or in a full state of ice pieces, and a fuse 1 g. Further, the icemaking device 1 is provided with a transmission mechanism fortransmitting a rotary output of the motor 5 to the rotary cam body 55, atorque limiter disposed at a midway position of the transmissionmechanism and the like as described below.

Next, a basic operation of the ice making device 1 will be describedbelow based on the chart shown in FIG. 6. First, after water has beensupplied to the ice tray 21 from the water-supply port 221, an icemaking operation is started in the ice tray 21. During this time, powersupply to the motor 5 and the heater 26 is stopped and the raking parts232 are stopped at the home position where the raking parts 232 areinclined on an opposite side to the water-supply port 221 as shown inFIG. 3(B). In this state, as shown in FIG. 4(A), the main switch 72 isin a first state where the thermostat 91 and the water-supply switch 73are in an “OFF” state. In addition, the ice detecting switch 71 islocated at a position showing an ice shortage state (first state).

After that, at the time of “T0”, when a monitoring result of thethermostat 91 for the ice tray 21 indicates that a temperature of theice tray 21 has become equal to a predetermined temperature or lower, asshown in FIG. 4(B), the thermostat 91 is turned to be in an “ON” stateand energization to the motor 5 and the heater 26 is started. As aresult, the rotary cam body 55 is turned and thus the raking member 23is started to turn in a direction shown by the arrow “A” in FIG. 3(B)and the heater 26 starts to warm the ice tray 21.

Next, at the time of “T1”, the main switch 72 is switched to a secondstate as shown in FIG. 4(C). However, even when the main switch 72 isswitched to the second state, the energization to the motor 5 and theheater 26 is continued. Therefore, the raking member 23 is driven by themotor 5 and tip end portions of the raking parts 232 are abutted withupper faces of ice pieces manufactured in the ice tray 21. However, atthis time, the temperature of the ice tray 21 may be low and thus an iceadhering force of the ice piece in the ice tray 21 is large. Therefore,turning of the raking member 23 is prevented by the ice pieces in theice tray 21 and the tip end portions of the raking parts 232 are stoppedin a state where that the tip end portions of the raking parts 232 areabutted with the upper faces of the ice pieces in the ice tray 21. Inaccordance with an embodiment, a torque limiter is disposed at a midwayposition of a power transmission route from the motor 5 to the rakingmember 23. Therefore, the motor 5 is capable of continuing to rotatewhile turning of the raking member 23 is stopped, and thus a torquelimited by the torque limiter 8 continues to act on the ice pieces.

When the ice pieces have been separated from the ice tray 21 by applyingheat with the heater 26, the raking member 23 connected with the rotarycam body 55 starts to turn in a direction where the ice pieces are rakedout and then an ice detecting operation is performed. At the time of“T2”, a tip end portion of the ice detecting lever 60 firstly movesupward from the ice storage part 1 a. As a result, as shown in FIG.4(D), the ice detecting switch 71 is temporarily switched from the firststate to the second state. At approximately same time, discharge of theice pieces is started and, after all of the ice pieces have fallen intothe ice storage part 1 a, at a time of “T3”, the tip end portion of theice detecting lever 60 moves down toward the ice storage part 1 a again.At this time, when the ice storage part 1 a is in an ice shortage state,the tip end portion of the ice detecting lever 60 is capable of beingmoved downward and thus, as shown in FIG. 4(C), the ice detecting switch71 is returned to the first state from the second state.

Next, at the time of “T4”, when a temperature of the ice tray 21 exceedsa predetermined temperature, a monitoring result of the thermostat 91for the ice tray 21 is, as shown in FIG. 5(A), changed to an “OFF” stateand energization to the heater 26 is stopped. However, energization tothe motor 5 is continued.

Next, at the time of “T5”, as shown in FIG. 5(B), when the water-supplyswitch 73 is changed to an “ON” state, the water-supply valve 220 ischanged to an open state to supply water to the ice tray 21 through thewater-supply port 221. In this case, since a resistance value of theheater 26 is small, the heater 26 is utilized as a part of electricwiring when the water-supply valve 220 is energized. At this time, theraking parts 232 have already passed near the water-supply port 221 andare located on a side in an inclined state which is opposite to the sidewhere the water-supply port 221 is disposed.

Next, at the time of “T6”, as shown in FIG. 5(C), since the water-supplyswitch 73 is changed to an “OFF” state, the water-supply valve 220 ischanged to a closed state and water-supply to the ice tray 21 throughthe water-supply port 221 is stopped. Next, at the time of “T7”, powersupply to the motor 5 is stopped and the raking parts 232 are stopped atthe home position where the raking parts 232 are inclined on theopposite side to the water-supply port 221. In the meantime, the mainswitch 72 is returned to the first state as shown in FIG. 4(A). Further,ice making is performed in the ice tray 21 again and then theabove-mentioned operation is repeated.

In the embodiment described above, after the tip end portion of the icedetecting lever 60 has been moved upward from the ice storage part 1 aat the time of “T2” and then, its tip end portion is going to movedownward to the ice storage part 1 a again at the time of “T3”. In thiscase, when the ice storage part 1 a is in an ice full state, the tip endportion of the ice detecting lever 60 cannot move downward and thus theice detecting switch 71 remains to be in the second state as shown inFIG. 4(D). However, also in this state, energization to the heater 26and the motor 5 is continued and thus operation for returning to thehome position is performed. In subsequent operations, when the icestorage part 1 a is in the ice full state, as shown in FIG. 5(D), theice detecting switch 71 remains to be in the second state. Therefore,even when a temperature of the ice tray 21 becomes equal to apredetermined temperature or lower to cause the thermostat 91 to bechanged to an “ON” state, energization to the heater 26 and the motor 6is not performed. Accordingly, after quantity of ice pieces in the icestorage part 1 a has been reduced and the ice detecting switch 71 ischanged to the first state from the second state, energization to theheater 26 and the motor 6 is started.

As described above, in the ice making device 1 in accordance with thisembodiment, ice pieces can be successively manufactured and the icepieces manufactured can be automatically discharged to the ice storagepart 1 a which is disposed downward. Further, ice quantity is detectedin the ice storage part 1 a and, when the ice storage part 1 a is in anice full state, discharging of ice pieces to the ice storage part 1 a isnot performed and thus the ice pieces do not overflow from the icestorage part 1 a.

Further, in this embodiment, when the raking parts 232 are passedthrough near the water-supply port 221 and, in addition, passed throughjust above the rotation shaft 31 and then reached to a position wherethe raking parts 232 are inclined on an opposite side to thewater-supply port 221, the drive unit 3 starts to supply water from thewater-supply port 221 to the ice tray 21. Therefore, a state is avoidedwhere water is splashed on the raking parts 232 at the time ofwater-supply to cause the water to be frozen and, as a result, the icetray 21 and the raking parts 232 are prevented to be frozen with eachother.

Further, since the home position of the raking parts 232 is set on anopposite side to the side where the water-supply port 221 is arrangedwith respect to the rotation shaft 231, the water-supply part 22 is notdisposed near the raking parts 232 which are stopped at the homeposition. Therefore, when confirmation of an operation of the rakingmember 23 is performed by manually pressing the raking parts 232 from anupper side to turn it in the direction shown by the arrow “A”, theoperation is not disturbed by the water-supply part 22 and thus theoperation can be easily confirmed.

Further, since the home position of the raking parts 232 is set on theopposite side to the side where the water-supply port 221 is arrangedwith respect to the rotation shaft 231, when the raking parts 232 aredepressed, the raking member 23 is turned so as to rake out in thedirection shown by the arrow “A” and thus the operation can be easilyconfirmed. In other words, as a comparison example, when the homeposition of the raking parts 232 are set, for example, at a positionshown in FIG. 3(C), in order to turn the raking member 23 in thedirection as shown by the arrow “A”, it is required that a finger isinserted between the raking parts 232 to turn it up. However, accordingto the embodiment of the present invention, the troublesome operation asdescribed above is not required.

FIG. 7 is an explanatory view showing the inner case which is used inthe drive unit and structural members disposed in the inner case in theice making device in accordance with the embodiment. FIG. 8(A) is a sideview showing a rotary cam body which is shown in FIG. 7.

As shown in FIG. 3(A), the drive unit 3 is provided with a case body 4.The motor 5, the main switch 72 structured of leaf switches, thewater-supply switch 73 structured of leaf switches, the ice detectingswitch 71 structured of leaf switches and the like which are describedwith reference to FIG. 4(A) are disposed in the inside of the case body4. In this embodiment, the case body 4 includes an inner case 41 formedin a rectangular measure shape, a base plate 42 (first partition wall)and an outer case 43 formed in a rectangular measure shape. The casebody 4 is formed by superposing edge parts of the inner case 41 and theouter case 43 on each other from both the right and left sides so as tosandwich the base plate 42. In this state, a first space 46 ispartitioned and formed between the inner case 41 and the base plate 42and a second space 47 is partitioned and formed between the outer case43 and the base plate 42. The first space 46 and the second space 47 arerespectively used for disposing following mechanisms and the like.

As shown in FIG. 7, the thermostat 91 is fixed at a bottom part of theinner case 41 in the first space 46 between the inner case 41 and thebase plate 42. Further, in the ice making device 1 in this embodiment,as shown in FIG. 2(B), terminal parts 262 (engagement part forconnection), which are made of an electrically insulator such as rubber,of the heater 26 are protruded from the ice tray 21 toward the driveunit 3. Further, as shown in FIG. 7, the case body 4 of the drive unit 3is formed with recessed parts 411 (engaged portion for connection) whichopen toward an outer side of the inner case 41 at the bottom part of theinner case 41 on both side positions of the thermostat 91. A throughhole 412 is formed in the back of the recessed part 411. Further, aconnection terminal 92 is disposed at the bottom part of the inner case41 so as to expose in the through hole 412. Therefore, after the driveunit 3 and the ice making unit 2 have been respectively assembled, theterminal parts 262 protruding from the ice tray 21 are fitted to therecessed parts 411 of the inner case 41 and, as a result, the ice makingunit 2 and the drive unit 3 are connected with each other and theterminals 261 of the heater 26 are electrically connected with theconnection terminals 92 at the fitting portions of the terminal parts262 to the recessed parts 411. Further, an earth (ground) member 45 isdisposed on an outer side of the bottom part of the inner case 41 at aposition which is capable of abutting with the ice tray 21. When aportion where the earth member 45 is disposed is fixed to the ice tray21 with a metal screw for earth (ground) connection in the inner case41, ground connection to the ice tray 21 can be performed. In thisstate, since the thermostat 91 is abutted with a temperature detectingpart 219 of the ice tray 21, the temperature of the ice tray 21 can bemonitored. In addition, when the ice making unit 2 is connected with thedrive unit 3, the “D”-shaped portion 230 of the rotation shaft 231 isfitted into a hole formed in “D”-shape of the rotary cam body 55 whichis disposed in the inside of the case body 4. Therefore, the drive unit3 and the ice making unit 2 are mechanically connected with each other.

As described above, in the ice making device 1 in accordance with thisembodiment, when the ice making unit 2 is to be connected with the driveunit 3, members required to be electrically connected are only theterminals 261 of the heater 26 and the connection terminals 92.Therefore, the drive unit 3 and the ice making unit 2 are connected witheach other only by fitting the terminal parts 262 (engagement part forconnection) protruding from ice tray 21 to the recessed parts 411(portion to be engaged for connection) of the inner case 41, and theterminals 261 of the heater 26 and the connection terminals 92 areautomatically connected with each other. Further, when the ice makingunit 2 is to be connected with the drive unit 3, members required to bemechanically connected are only the rotation shaft 231 and the rotarycam body 55 and, when the ice making unit 2 is connected with the driveunit 3, the “D”-shaped portion 230 of the rotation shaft 231 isautomatically fitted into the connection hole 557 of the rotary cam body55 whose inlet portion is formed in a “D”-shape in cross-section.

Therefore, after the ice making unit 2 and the drive unit 3 have beenseparately assembled, the ice making device 1 can be assembled only byconnecting the ice making unit 2 with the drive unit 3. Accordingly,assembling steps can be simplified in comparison with a case thatmembers for structuring the drive unit are successively and separatelyassembled to the ice making unit 2.

Further, according to the embodiment of the present invention, the icemaking unit 2 and the drive unit 3 are connected with each other afterthe ice making unit 2 and the drive unit 3 have been separatelymanufactured. Therefore, different from a comparison method in which,after respective members are successively mounted on the ice tray 21 tocomplete the drive unit, a heater is mounted on the ice tray, in theembodiment of the present invention, fragments and dirt sticking to theice tray 21 which structures the ice making unit 2 can be reduced andthus sanitary quality in the ice making device 1 is improved.

In addition, after the drive unit 3 and the ice tray 21 have beenconnected, it is difficult that the ice tray 21 is integrated with theheater 26 by caulking or insert-molding. However, according to thisembodiment, after the ice tray 21 and the heater 26 have been integratedwith each other by caulking or insert-molding, the ice making unit 2 isassembled and, after that, the ice making unit 2 can be connected withthe drive unit 3.

Further, in the ice making device 1 in accordance with this embodiment,the earth (ground) member 45 is disposed on the outer side of the innercase 41 at the position where the earth member 45 is capable of abuttingwith the ice tray 21. Therefore, when the portion of the inner case 41where the earth member 45 is disposed is fixed to the ice tray 21 with ametal screw having electroconductivity, grounding treatment of the icemaking device 1 can be performed easily.

As shown in FIG. 3(A), one side portion of the rotary cam body 55 isdisposed at the bottom part of the inner case 41 in the first space 46formed between the inner case 41 and the base plate 42. An upper endside, i.e., the other side of the rotary cam body 55 is protruded intothe second space 47 formed between the base plate 42 and the outer case43 through the through hole 421 formed in the base plate 42.

In the first space 46 formed between the inner case 41 and the baseplate 42, as shown in FIG. 7, the motor 5 is disposed at the bottom partof the inner case 41 on a side of the rotary cam body 55. An ACsynchronous motor is, for example, used as the motor 5. A transmissionmechanism 50 for transmitting rotation of the motor 5 to the rotationshaft 231 of the ice making unit 2 is formed in the first space 46. Thetransmission mechanism 50 includes a rotor pinion 51 which is rotatablysupported by a fixed shaft of the motor 5, a torque limiter 8 providedwith an outer teeth gear 502 (input part) having a large diameter whichis engaged with the rotor pinion 51, a chipped tooth gear 503structuring an output part of the torque limiter 8, a gear body 52provided with an outer teeth gear 504 having a large diameter which isdriven by the chipped tooth gear 503, a gear body 53 provided with anouter teeth gear 506 having a large diameter which engages with an outerteeth gear (not shown) having a small diameter of the gear body 52, andthe rotary cam body 55 provided with an outer teeth gear 54 having alarge diameter which is engaged with an outer teeth gear 507 having asmall diameter of the gear body 53. The tip end portion of the fixedshaft of the motor 5 is supported by the base plate 42. Support shaftswhich rotatably support the torque limiter 8, the gear body 52 and thegear body 53 are supported by an end plate 5 a of the motor 5 and thebase plate 42. The rotary cam body 55 is rotatably supported by thebottom part of the inner case 41 and the base plate 42.

As shown in FIG. 8(A), the rotary cam body 55 is provided with acylindrical part 551 extending downward, i.e., the ice making unit 2side from the outer teeth gear 54. The cylindrical part 551 is formedwith a coupling hole 557 in a “D”-shape in cross section at its inletportion. The “D”-shaped portion 230 of the rotation shaft 231 is fittedinto the coupling hole 557 to transmit rotation of the rotary cam body55 to the rotation shaft 231.

FIG. 9(A) is a plan view showing the torque limiter which is provided inthe ice making device in accordance with an embodiment of the presentinvention and FIG. 9(B) is its exploded perspective view.

In the ice making device 1 in this embodiment, when the raking parts 232formed on the rotation shaft 231 of the ice making unit 2 is going tomove to rake ice pieces formed in the ice tray 21 out, the ice piecesmay not be separated from the ice tray 21 immediately after heating isstarted by the heater 26. In this state, when the rotation shaft 231 isturned to going to rake the ice pieces in the ice tray 21 out by theraking parts 232, a large load is applied to the raking parts 232 byunmoved ice pieces. Therefore, an excessive load is applied to thetransmission mechanism 50 for transmitting a rotary force of the motor 5to the rotation shaft 231 and thus a gear structuring the transmissionmechanism 50 may be damaged. In order to prevent the problem describedabove, in this embodiment, as shown in FIG. 7, the torque limiter 8which will be described below is structured on a motor side of thetransmission mechanism 50.

As shown in FIG. 7 and FIGS. 9(A) and 9(B), the torque limiter 8includes a gear body 80 (first member) made of resin, a cup-shapedsliding member 84 (second member) made of resin, and a coil spring 85(ring-shaped urging member). The gear body 80 is provided with a largediameter circular plate part 81 formed with the outer teeth gear 502. Asmall diameter cylindrical part 82 is formed upright at a center portionof an upper face of the large diameter circular plate part 81 and alarge diameter cylindrical part 83 is formed so as to surround the smalldiameter cylindrical part 82. The gear body 80 is formed with a shafthole 811 so as to penetrate through the large diameter circular platepart 81 and the small diameter cylindrical part 82. A support shaft (notshown) whose both ends are supported by the end plate 5 a of the motor 5and the base plate 42 is fitted to the shaft hole 811. Therefore, thegear body 80 is capable of being driven by the rotor pinion 51 to berotated around the support shaft.

The sliding member 84 is formed in a cup shape which opens toward thegear body 80. The sliding member 84 includes an upper base part 847(bottom plate part) and a cylindrical drum part 845 extendingperpendicularly downward from an outer peripheral edge of the upper basepart 847. Therefore, in a state where the sliding member 84 is assembledon the gear body 80, the cylindrical drum part 845 of the sliding member84 is fitted so as to surround a circumferential face of the largediameter cylindrical part 83 of the gear body 80. The upper base part847 of the sliding member 84 is formed in a multi-stage shape includinga large diameter part 841, a middle diameter part 842 and a smalldiameter part 843 which are formed in this order. A chipped tooth gear503 is formed on a side face of the small diameter part 843. A hole intowhich the small diameter cylindrical part 82 of the gear body 80 isfitted is formed in the inside of the large diameter part 841 and themiddle diameter part 842. The small diameter part 843 is formed with ashaft hole 840 into which a support shaft penetrating through the smalldiameter cylindrical part 82 is fitted. Therefore, the sliding member 84is also rotatable around the support shaft. In this case, the slidingmember 84 is supported by the small diameter cylindrical part 82.

An inner diameter dimension of the cylindrical drum part 845 of thesliding member 84 is set to be a little larger than the outer diameterdimension of the large diameter cylindrical part 83 of the gear body 80to have a specified clearance between them. The cylindrical drum part845 of the sliding member 84 is formed with three cutout parts 84 awhich are extended in an axial direction from its tip end portion withan equal angular interval. Therefore, the cylindrical drum part 845 isdivided into three elastic plate parts 846 in a tongue shape which areseparated in a circumferential direction by the cutout parts 84 a.Accordingly, in a state that the sliding member 84 is assembled on thegear body 80 such that the cylindrical drum part 845 surrounds aroundthe large diameter cylindrical part 83 of the gear body 80, when thecoil spring 85 is mounted around the cylindrical drum part 845 (elasticplate parts 846), the elastic plate parts 846 are elastically deformedto an inner side or a center side to abut with the outer circumferentialface of the large diameter cylindrical part 83. As a result, when thegear body 80 is rotated and a large load is not applied to the slidingmember 84, the sliding member 84 is rotated together with the gear body80. On the contrary, when the gear body 80 is rotated but a large loadis applied to the sliding member 84, slip occurs between the elasticplate parts 846 and the large diameter cylindrical part 83 and thusrotation of the gear body 80 is not transmitted to the sliding member84.

The coil spring 85 is mounted only at a lower end portion of thecylindrical drum part 845 (tip end portions of the elastic plate parts846). The cutout part 84 a is extended to a root portion of the largediameter part 841 in the upper base part 847 of the sliding member 84,and the upper base part 847 is also divided into three portions by thecutout parts 84 a to form base parts of the elastic plate part 846.Therefore, the elastic plate part 846 of the sliding member 84 is formedin a perpendicularly bent shape from the upper base part 847 and, inaddition, an axial dimension of the cylindrical drum part 845 is set tobe longer than a dimension in a radial direction of the upper base part847. Accordingly, the elastic plate part 846 has a high rigidity in thecircumferential direction but its rigidity in the radial direction islow and thus the elastic plate part 846 can be elastically deformedeasily toward a center side. Further, in order to make the elastic plateparts 846 easily and elastically deformed on a center side, the cutoutpart 84 a which is formed from the tip end of the cylindrical drum part845 to a middle portion of the upper base part 847 is formed such that alength of the cutout part formed in the cylindrical drum part 845 islonger than a length of the cutout part formed in the upper base part847.

As described above, in the ice making device 1 in this embodiment, thetorque limiter 8 is structured at a first stage of the transmissionmechanism 50 (on the side nearer to a drive source in the transmissionmechanism 50) and thus a torque applied to the torque limiter 8 issmall.

In the sliding member 84 of the torque limiter 8, the cutout part 84 ais formed from the cylindrical drum part 845 to the upper base part 847.Therefore, since the length of the elastic plate part 846 is long, theelastic plate part 846 has a high rigidity in the circumferentialdirection but has a low rigidity in the radial direction. Accordingly,the elastic plate parts 846 are easily bent resiliently when the coilspring 85 is mounted around the cylindrical drum part 845. As a result,rigidity of the elastic plate part 846 does not exert large influence onthe friction torque and the friction torque is roughly determined onlyby an urging force of the coil spring 85. Therefore, when dimension ofthe gear body 80 made of resin and dimension of the cup-shaped slidingmember 84 made of resin are varied, or even when rigidity of the elasticplate part 846 is varied with an elapse of time or due to ambienttemperature, the variation of the friction torque is reduced.Especially, the ice making device 1 in this embodiment is used in arefrigerator or in a freezer and, on the other hand, the ice makingdevice 1 is often warmed by the heater 26. Therefore, the rigidity ofthe elastic plate part 846 made of resin is easily varied but, even inthis case, the torque limiter 8 is operated surely.

In this embodiment, only the tip end portions of the elastic plate parts846 are pressed by the coil spring 85 toward the outer circumferentialface of the large diameter cylindrical part 83 and thus the elasticplate parts 846 are easily deformed. Moreover, the torque limiter 8 issimply structured and thus effect of accuracy of its structural parts issmall. Further, when a spring having a small spring constant can be usedas the coil spring 85 so as to be elastically deformed largely, thetorque limiter 8 is surely operated even though part accuracy of thesliding member 84 is low. In addition, since the coil spring 85 canprovide a stable urging force, a stable friction torque is obtained.

In this embodiment, it is structured that the large diameter part 841,the middle diameter part 842 and the small diameter part 843 aresuperposed in this order on the upper base part 847 of the slidingmember 84. A hole into which the small diameter cylindrical part 82 ofthe gear body 80 is fitted is formed on an inner side of the largediameter part 841 and the middle diameter part 842. Further, the smalldiameter part 843 is formed with a shaft hole 840 into which the supportshaft penetrating through the small diameter cylindrical part 82 isfitted. Therefore, the sliding member 84 and the gear body 80 aresupported by the common support shaft and the sliding member 84 isrotated in a state that the sliding member 84 is supported by the smalldiameter cylindrical part 82 of the gear body 80. Accordingly, thesliding member 84 and the gear body 80 are rotated with surelymaintaining a coaxial state.

FIG. 10 is an explanatory view showing the base plate used in the driveunit and structural members which are disposed on the outer case side ofthe base plate in the ice making device in the embodiment.

In this embodiment, an ice detecting mechanism 6 for detecting icequantity in the ice storage part 1 a through the ice detecting lever 60shown in FIG. 1 is structured by utilizing the first space 46 betweenthe inner case 41 and the base plate 42 and the second space 47 betweenthe base plate 42 and the outer case 43, which are shown in FIG. 3(A).

In this embodiment, the ice detecting mechanism 6 includes generally, anice detecting lever drive mechanism 65 as shown in FIG. 7 which isstructured by utilizing the first space 46 between the inner case 41 andthe base plate 42, and an ice detecting lever position detectingmechanism 75 which is structured by utilizing the second space 47between the base plate 42 and the outer case 43, and an ice detectingswitch 71 which is structured by utilizing the second space between thebase plate 42 and the outer case 43, which are shown in FIG. 10. “ON”and “OFF” operations of the ice detecting switch 71 are performed by theice detecting lever position detecting mechanism 75.

As shown in FIG. 7 and FIG. 8(A), the lever drive mechanism 65 includesa cam part 552 formed around a cylindrical part 551 which is formed on alower end side of the rotary cam body 55, a first drive lever 61 whichis driven by a cam face of the cam part 552 to move the ice detectinglever 60, a coiled torsion spring 66 which urges the first drive lever61, and a second drive lever 62 which holds an end part of the icedetecting lever 60.

The first drive lever 61 is provided with a pawl part 611 capable ofabutting with the cam part 552, a cylindrical support shaft 612extending in an axial direction, and a transmitting part 614 which islocated on an opposite side to the pawl part 611 with respect to thesupport shaft 612. A “U”-shaped cutout part 613 is formed in thetransmitting part 614. Therefore, when the rotary cam body 55 is turnedby rotation of the motor 5 to turn the cam part 552, the pawl part 611is pushed by the cam part 552 and the first drive lever 61 is turnedaround the support shaft 612 by a specified angle in a direction shownby the arrow “C1” in FIG. 7 against an urging force of the coiledtorsion spring 66. Further, when a small diameter portion of the camface abuts with the pawl part 611, the first drive lever 61 is turnedaround the support shaft 612 in a reverse direction shown by the arrow“C2” by the urging force of the coiled torsion spring 66 to return toits original position.

The second drive lever 62 is provided with a cylindrical part 621 havinga slit 621 a for holding an end part of the ice detecting lever 60, atransmitting projection 623 which is protruded from a side face of thecylindrical part 621, and a small projection 622 which is protruded fromthe side face of the cylindrical part 621 on an opposite side to thetransmitting projection 623. A pin 623 a which is protruded from anunder face of the transmitting projection 623 is fitted into a“U”-shaped cut-out part 613 which is formed in the first drive lever 61.Therefore, when the first drive lever 61 is turned in the directionshown by the arrow “C1”, the second drive lever 62 is turned around thecylindrical part 621 in the direction shown by the arrow “D1”. On theother hand, when the first drive lever 61 is turned in the directionshown by the arrow “C2”, the second drive lever 62 is turned around thecylindrical part 621 in the direction shown by the arrow “D2”. As aresult, the ice detecting lever 60 is driven. In accordance with thisembodiment, the base plate 42 is formed with a stopper 629 a, whichprevents the transmitting projection 623 of the second drive lever 62from turning more than a prescribed position in the direction shown bythe arrow “D2”, and a stopper 629 b which prevents the transmittingprojection 623 from turning more in the direction shown by the arrow“D1”.

A flat spring 63 is disposed at a side position of the cylindrical part621 and, when the ice detecting lever 60 is lifted upward with a manualoperation, the small projection 622 of the second drive lever 62 goesover a projected part 63 a of the flat spring 63 to maintain a liftedstate of the ice detecting lever 60. As a result, the ice making device1 becomes to be a similar state to the ice full state and thus anoperation of the ice making device 1 is stopped.

As shown in FIG. 10, an upper half portion of the cylindrical part 621of the second drive lever 62 is penetrated through the base plate 42 andlocated at a second space 47 between the base plate 42 and the outercase 43. The ice detecting lever position detecting mechanism 75includes a projection 625 (engagement part) that is formed on the outerperipheral face of an upper end portion of the cylindrical part 621(rotation shaft) in the second drive lever 62 (driving member), a drivenring 751 (driven member) which is put on around the upper end of thecylindrical part 621 on the base plate 42, and a pressing lever 753(transmitting member) whose positions are changed by a protruded part752 which is protruded from an outer peripheral face (cam face) of thedriven ring 751. The pressing lever 753 is provided with a cylindricalpart 753 a which is fitted to a protruded part that is formed in thebase plate 42, a connection part 753 b which is extended from thecylindrical part 753 a, a first protruded part 753 c which protrudes tothe driven ring 751 side from a tip end portion of the connection part753 b, and a second protruded part 753 d which protrudes to an oppositeside to the first protruded part 753 c from the tip end part of theconnection part 753 b.

In the ice detecting lever position detecting mechanism 75, a cut-outpart 755 (recessed part) which is extended in a peripheral direction isformed on a rear face side of the protruded part 752 of the driven ring751 and on an inner peripheral side of a hole through which thecylindrical part 621 is penetrated. The projection 625 that is formed onthe cylindrical part 621 of the second drive lever 62 is located withinthe inside of the cut-out part 755 with a constant play to end parts 755a and 755 b in the peripheral direction of the cut-out part 755.Therefore, a transmission part through which movement of the seconddrive lever 62 is transmitted to the driven ring 751 is formed betweenthe second drive lever 62 and the driven ring 751 so as to be apart fromeach other in the peripheral direction by a prescribed dimension.

In the ice detecting lever position detecting mechanism 75 structured asdescribed above, when the second drive lever 62 is turned in thedirection of the arrow “D1” (when the ice detecting lever 60 is lifted),the movement of the second drive lever 62 is transmitted to the drivenring 751 by the projection 625 which abuts with the end part 755 blocated on the side shown by the arrow “D1” in the peripheral directionof the cut-out part 755. As a result, the driven ring 751 is turned inthe direction shown by the arrow “D1” in conjunction with the seconddrive lever 62. Accordingly, the first protruded part 753 c of thepressing lever 753 is moved from a state, that the first protruded part753 c abuts with a peripheral face (low portion of the driven member) ofthe driven ring 751 where the protruded part 752 is not formed, to astate that the first protruded part 753 c abuts with a slant face 752 dof the protruded part 752, which is just before abutting with an outerperipheral face of the protruded part 752 (high portion of the drivenmember). As a result, the pressing lever 753 is turned around thecylindrical part 753 a in a direction shown by the arrow “E1” and thesecond protruded part 753 d causes the ice detecting switch 71 toperform “ON” and “OFF” operation.

In this embodiment, the ice detecting switch 71 is a leaf switch whichis comprised of three leaf contact pieces 711, 712 and 713. The pressinglever 753 abuts with only the leaf contact piece 711 among three leafcontact pieces 711, 712 and 713 to cause it to move. More specifically,when the second protruded part 753 d of the pressing lever 753 is in anon-abutting state, the leaf contact piece 711 is abutted with an endpart 713 a of the leaf contact piece 713 which is extended to anopposite side to the leaf contact piece 711 with respect to the leafcontact piece 712 so as to face the leaf contact piece 711 and thus theleaf contact piece 711 and the leaf contact piece 713 are in a contactstate with each other. On the other hand, when the leaf contact piece711 is pressed by the second protruded part 753 d of the pressing lever753, the leaf contact piece 711 is deformed to a side of the leafcontact piece 712 and thus the leaf contact piece 711 is moved apartfrom the end part 713 a of the leaf contact piece 713 to be in a contactstate with the leaf contact piece 712.

In the ice detecting mechanism 6 structured as described above, the leafcontact piece 711 is abutted with the end part 713 a of the leaf contactpiece 713 before the motor 5 is started and rotated. In order to detectan ice quantity in the ice storage part 1 a, when the rotary cam body 55is turned by the motor 5 to turn the first drive lever 61 in thedirection shown by the arrow “C1”, the second drive lever 62 is turnedaround the cylindrical part 621 in the direction shown by the arrow“D1”. As a result, the ice detecting lever 60 is turned as shown by thearrow “F1” in FIGS. 3(A) and 3(B), and its end part goes up. In thiscase, the second drive lever 62 is turned in the direction shown by thearrow “D1” and the driven ring 751 is also turned in the direction shownby the arrow “D1”. Therefore, the protruded part 752 of the driven ring751 is abutted with the first protruded part 753 c of the pressing lever753 to cause the pressing lever 753 to turn in the direction shown bythe arrow “E1” and a state is obtained where the leaf contact piece 711is contacted with the leaf contact piece 712. Further, in a state thatthe pressing lever 753 is abutted with the protruded part 752 of thedriven ring 751, the leaf contact pieces 711 and 712 are stablycontacted with each other.

When the rotary cam body 55 is further turned by the rotation of themotor 5, the first drive lever 61 is turned in a reverse direction shownby the arrow “C2” and the second drive lever 62 is going to turn aroundthe cylindrical part 621 in a direction shown by the arrow “D2”. As aresult, the ice detecting lever 60 is going to turn and go down as shownby the arrow “F2” in FIGS. 3(A) and 3(B).

In this case, when ice pieces are insufficient in the ice storage part 1a, moving of the ice detecting lever 60 downward is permitted and thusthe second drive lever 62 is capable of turning in the direction shownby the arrow “D2” to cause the protruded part 625 to press the end part755 a of the cutout part 755 and thus the driven ring 751 is turned inthe direction shown by the arrow “D2”. Accordingly, when a timing atwhich the first protruded part 753 c of the pressing lever 753 starts toabut with the slant face 752 a of the protruded part 752 of the drivenring 751 is set to be a boundary position between a shortage state and afull state of ice pieces in the ice storage part 1 a, ice quantity inthe ice storage part 1 a can be detected on the basis of an “ON” or“OFF” operation by using the ice detecting switch 71.

In this embodiment, the driven ring 751 is moved with a play withrespect to the second drive lever 62. Therefore, even when the seconddrive lever 62 starts' to turn in a reverse direction shown by the arrow“D2” after the second drive lever 62 has been turned in the directionshown by the arrow “D1”, the protruded part 625 moves only in the insideof the cutout part 755 and thus the driven ring 751 is not moved.However, since the leaf contact piece 711 applies an urging force, whichis going to cause the leaf contact piece 711 to return from itselastically deformed state, to the pressing lever 753, when the seconddrive lever 62 is turned in the direction shown by the arrow “D2”, thepressing lever 753 presses the slant face 752 a formed in the protrudedpart 752 of the driven ring 751 to move the driven ring 751 in thedirection shown by the arrow “D2”. Therefore, the driven ring 751 ismoved before the driven ring 751 is driven by the second drive lever 62.Accordingly, the leaf contact piece 711 can be quickly returned from theelastically deformed state even before the driven ring 751 is driven bythe second drive lever 62. As a result, in the ice detecting switch 71,the leaf contact piece 711 quickly returns to a state where the leafcontact piece 711 contacts with the end part 713 a of the leaf contactpiece 713. Therefore, even when an operation is transmitted to the icedetecting switch 71 through the cam mechanism, an unstable region is notoccurred in the ice detecting switch 71 where a state that the leafcontact pieces 711, 712, 713 are contacted is not clearly different froma state that they are separated. Accordingly, an electric obstacle doesnot occur.

When ice pieces are in a full state in the ice storage part 1 a, movingof the ice detecting lever 60 downward is prevented by the ice pieces.Therefore, turning of the second drive lever 62 in the direction shownby the arrow “D2” is prevented and thus the leaf contact piece 711maintains to have contacted with the leaf contact piece 712. After theice detecting lever 60 is prevented from moving down by the ice pieces,the first drive lever 61 is prevented from turning in the directionshown by the arrow “C2”. Therefore, the pawl part 611 of the first drivelever 61 does not follow the cam part 552 of the rotary cam body 55 inthe “C2” direction and thus the ice detecting lever 60 does not go downfrom a position restricted by the ice pieces even when the rotary cambody 55 is turned.

FIG. 8(B) is an explanatory perspective view showing three leaf contactpieces which structure the main switch 72 for the ice making device. Inthis embodiment, the main switch 72 is structured by utilizing thesecond space 47 formed between the base plate 42 and the outer case 43shown in FIG. 3(A). In order to structure the main switch 72, an upperhalf portion of the rotary cam body 55 is utilized which protrudes fromthe first space 46 to the second space 47 through the through hole 421of the base plate 42. In other words, the rotary cam body 55 includes alarge diameter part 553 formed in a cylindrical shape, a middle diameterpart 554 having a smaller diameter than the large diameter part 553, afirst cam part 558 having a smaller diameter than the middle diameterpart 554, a second cam part 559 having a smaller diameter than the firstcam part 558, and a small diameter part 555 having a smaller diameterthan the second cam part 559, which are formed upward in this order tobe in a multistage shape from the outer teeth gear 54. This multistageportion is disposed in the second space 47. Both of side faces of thefirst cam part 558 and the second cam part 559 are formed to be camfaces provided with stepped parts 558 b and 559 b whose diameters aresharply varied in their circumferential direction. The diameters ofthese cam faces increase in a direction shown by the arrow “B” from thestepped parts 558 b and 559 b. Further, positions of the stepped parts558 b and 559 b of the first cam part 558 and the second cam part 559are shifted from each other in a circumferential direction and thestepped part 559 b is located backward to the stepped part 558 b in thedirection shown by the arrow “B”. In this embodiment, the middlediameter part 554 is formed with a protruded part 556 for operating aleaf contact piece of a water-supply switch 73 described below.

As shown in FIGS. 8(A) and 8(B), three leaf contact pieces 721, 722 and723 which structure the main switch 72 (leaf switch) for the ice makingdevice are disposed on the base plate 42 so as to extend toward therotary cam body 55. The leaf contact piece 723 is disposed at a positionnearest to a center axial line of the rotary cam body 55, the leafcontact piece 722 is disposed on its outer side, and the leaf contactpiece 721 is disposed on its further outer side. A tip end part 723 c ofthe leaf contact piece 723 is elastically abutted with a side face ofthe second cam part 559. Further, in an initial state, a tip end part722 c of the leaf contact piece 722 is dropped in a low portion of thestepped part 558 b to elastically contact with the leaf contact piece723. On the other hand, a tip end part 721 c of the leaf contact piece721 is elastically abutted with a side face of the first cam part 558.

The leaf contact piece 723 is straightly and horizontally extended fromits base end side and then perpendicularly turned upward and, afterthat, the leaf contact piece 723 is extended horizontally again. A loweredge of the tip end part 723 c is capable of sliding on an upper face ofthe first cam part 558.

The leaf contact pieces 721 and 222 are formed in a shape such thattheir base end portions are straightly extended at the same heightposition as that of the base end portion of the leaf contact piece 723and the widths of the tip end parts 721 c and 722 c are enlarged in anupward direction. Upper edge portions of the tip end parts 721 c and 722c are set at the same height position as that of the upper edge portionof the tip end part 723 c of the leaf contact piece 723. Further, afront edge of the leaf contact piece 721 is slightly extended andprotruded to a front end side from a front edge of the leaf contactpiece 722. When the rotary cam body 55 is turned in the direction asshown by the arrow “B”, the tip end parts 721 c and 722 c of the leafcontact pieces 721 and 222 structured as described above move along theside face of the first cam part 558 and the underside edges of the tipend parts 721 c and 722 c slide on the upper face of the middle diameterpart 554.

In an initial state of the main switch 72 structured as described above,the leaf contact piece 723 is located at a higher portion of the steppedpart 559 b and the leaf contact piece 722 is located at a lower portionof the stepped part 558 b and thus the leaf contact piece 722 contactswith the leaf contact piece 723. When the rotary cam body 55 is turnedin the direction shown by the arrow “B” from this state, the tip endpart 723 c of the leaf contact piece 723 drops on a lower portion of thestepped part 559 b and thus the leaf contact piece 722 is separated fromthe leaf contact piece 723. Further, immediately before the tip end part723 c of the leaf contact piece 723 drops on the lower portion of thestepped part 559 b, the tip end part 721 c of the leaf contact piece 721drops on a lower portion of the stepped part 558 b and thus the leafcontact piece 721 is connected to the leaf contact piece 722. When therotary cam body 55 is further turned in the direction as shown by thearrow “B”, the leaf contact pieces 721, 722 and 723 will be shifted to astate that they are located at higher portions of the stepped parts 559b and 558 b and then return to the initial state.

In this embodiment, a water supply switch 73 shown in FIG. 10 (leafswitch) is structured by utilizing a second space 47 between the baseplate 42 and the outer case 43 shown in FIG. 3(A). Similarly to the mainswitch 72, the water supply switch 73 is also structured by utilizingthe upper half portion of the rotary cam body 55 which protrudes intothe second space 47 from the first space 46 through the through hole 421of the base plate 42. In other words, a projection 556 is formed on aside face of the middle diameter part 554 and, on the other hand, twoleaf contact pieces 731 and 732 are extended toward the middle diameterpart 554 of the rotary cam body 55.

In the water supply switch 73 structured as described above, the leafcontact piece 731 is separated from the leaf contact piece 732 in theinitial state, which is in an “OFF” state. From this state, when therotary cam body 55 is turned in the direction shown by the arrow B andthe leaf contact piece 731 is pressed by the projection 556 toward theleaf contact piece 732, the leaf contact piece 731 and the leaf contactpiece 732 come into contact with each other to be in an “ON” state. Whenthe rotary cam body 55 is further turned in the direction shown by thearrow “B” and the leaf contact piece 731 returns to its originalposition, the leaf contact piece 731 is separated from the leaf contactpiece 732 to return to an “OFF” state.

In this embodiment, a water supply amount adjust mechanism 79 foradjusting “ON”/“OFF” timing with the water supply switch 73 isstructured on the base plate 42. The water supply amount adjustmechanism 79 is provided with an arch-shaped input lever 790 (operationmember) for adjusting a position of the leaf contact piece 732. Theinput lever 790 includes a cylindrical part 791 into which a supportshaft protruding from the base plate 42 is fitted, a pawl part 792abutting with the tip end part of the leaf contact piece 732 at its tipend side, and an operation part 793 protruding outside of the case body4 on an opposite side to the pawl part 792 with respect to thecylindrical part 791. When the operation part 793 is moved along an edgeof the base plate 42, as shown by the arrows “G1” and “G2”, the inputlever 790 is turned around the cylindrical part 791 to change theposition of the pawl part 792. Therefore, when the input lever 790 isturned in the direction shown by the arrow “G1”, the tip end side of theleaf contact piece 732 is resiliently bent in a direction which isseparated from the leaf contact piece 731 and thus a timing when thewater supply switch 73 is changed from an “OFF” state to an “ON” statebecomes late and a timing changed from the “ON” state to the “OFF” statebecomes early. Accordingly, a water supply time period from thewater-supply part 22 to the ice tray 21 which is described withreference to FIG. 1 is shortened and thus an amount of water supply tothe ice tray 21 is decreased to be capable of making smaller ice pieces.On the other hand, when the input lever 790 is turned in a directionshown by the arrow “G2”, the tip end side of the leaf contact piece 732is resiliently bent in a direction coming close to the leaf contactpiece 731 and thus a timing when the water supply switch 73 is changedfrom an “OFF” state to an “ON” state becomes early and a timing changedfrom the “ON” state to the “OFF” state becomes late. As a result, awater supply time period from the water-supply part 22 to the ice tray21 becomes longer and thus an amount of water supply to the ice tray 21is increased to be capable of making larger ice pieces.

An end portion of the input lever 790 near the operation part 793 isfitted into a “U”-shaped groove 795 a of the support plate 795. Thesupport plate 795 is structured so as to slide along an edge portion ofthe base plate 42. Further, the support plate 795 is formed with aprotruded part 795 b on its inner side face and, on the other hand, aplate part 420 which is formed along the edge portion of the base plate42 is formed with a plurality of grooves 420 a which is capable ofengaging with the protruded part 795 b. A click mechanism 79 a isstructured by the protruded part 795 b and the grooves 420 a. Therefore,when the input lever 790 is operated, the support plate 795 slides alongthe edge portion of the base plate 42 and the protruded part 795 b ofthe support plate 795 is moved over a portion between the grooves 420 aof the plate part 420 and thus a click feeling can be obtained. Inaddition, the input lever 790 is held at a prescribed position by theprotruded part 795 b engaging with the groove 420 a.

According to the water supply amount adjust mechanism 79 as describedabove, a spaced distance between the leaf contact pieces 731 and 732 canbe adjusted only by deforming the tip end side of the leaf contact piece732 to change its position and thus timings when the water-supply switch73 is turned “ON” or “OFF” can be adjusted. Therefore, when an amount ofwater (size of an ice piece) supplied to the ice tray 21 is to beadjusted, the amount of water can be easily adjusted from the outside,which is different from a case that a micro switch is used for thewater-supply switch 73. In addition, since both the water-supply switch73 and the water supply amount adjust mechanism 79 are mounted on thebase plate 42, assembling is easily performed with a high degree ofpositional accuracy. Further, as described below, both the leaf contactpieces 731 and 732 are held with the contact piece holding part 48 whichis structured on the base plate 42 and thus assembling is easilyperformed.

In accordance with an embodiment, both of the leaf contact pieces 731and 732 may be deformed as the water supply amount adjust mechanism 79and, alternatively, the leaf contact piece 731 which is driven by therotary cam body 55 may be deformed as the water supply amount adjustmechanism 79. However, in this embodiment, the leaf contact piece 732which is not moved by the rotary cam body 55 is deformed by the inputlever 790. Therefore, a timing of the leaf contact piece 731 which isdriven by the rotary cam body 55 is not varied and thus the water-supplyswitch 73 is surely operated.

Next, an operation of the drive unit will be briefly described belowwith reference to FIGS. 11(A) through 11(F) while related to a totaloperation described with reference to FIG. 3(A) through FIG. 5(D). FIGS.11(A) through 11(F) are explanatory views showing operations of thedrive unit.

In the initial state, positions of the rotary cam body 55, the firstdrive lever 61, the second drive lever 62, the pressing lever 753, theleaf contact piece 723, and the leaf contact piece 731 are set as shownin FIG. 11(A). In this state, a position of the ice detecting lever 60is located at the lowest position. Further, the raking parts 232 of theraking member 23 are located at an angle of about 20° with respect to ahorizontal direction.

At the time point of “TO” shown in FIG. 6, when the thermostat 91becomes to an “ON” state, energization to the motor 5 and the heater 26is started and the rotary cam body 55 is turned. As a result, the rakingmember 23 starts to turn in the direction shown by the arrow “A” in FIG.11(A).

Next, at the time point of “T1” shown in FIG. 6, as shown in FIG. 11(B),the leaf contact piece 721 is dropped from the step 558 b immediatelyafter the raking parts 232 have been located at an angle of about 10°with respect to the horizontal direction and thus the main switch 72 ischanged to the second state from the first state.

Next, at the time point of “T2” shown in FIG. 6, the turning of therotary cam body 55 is transmitted to the ice detecting lever 60 throughthe first drive lever 61 and the second drive lever 62 and, as shown bythe arrow “F1” in FIG. 11(C), the ice detecting lever 60 goes up.

Next, at the time period of “T3” shown in FIG. 6, the turning of therotary cam body 55 is transmitted to the ice detecting lever 60 throughthe first drive lever 61 and the second drive lever 62 and, when the icestorage part 1 a is in a shortage state of ice pieces, the ice detectinglever 60 goes down as shown by the arrow “F2” in FIG. 11(D).

Next, at the time point of “T5” shown in FIG. 6, the turning of therotary cam body 55 is transmitted to the leaf contact piece 731 andwater is supplied to the ice tray 21 during the time periods shown inFIGS. 11(E) and 11(F). Then, the rotary cam body 55, the first drivelever 61, the second drive lever 62, the pressing lever 753, the leafcontact piece 723, the leaf contact piece 731 and the like return totheir original positions.

FIG. 12 is an explanatory view showing the outer case used in the icemaking device in accordance with an embodiment which is viewed from anouter side. In this embodiment, the ice detecting switch 71, the mainswitch 72 and the water-supply switch 73 is structured by using astrip-shaped leaf contact pieces 711, 712, 721, 722, 723, 731 and 732which are formed of a metal plate that is worked in a predeterminedshape. The base end sides of the leaf contact pieces are formed, asshown by the leaf contact pieces 721, 722 and 723 in FIG. 8(B), in astrip shape such that their opposite sides to each other are parallel toeach other in a widthwise direction and their width dimensions of thebase end sides of the leaf contact pieces are equal to each other.Therefore, in this embodiment, all of the leaf contact pieces 711, 712,721, 722, 723, 731 and 732 are held by utilizing the contact pieceholding part 48 which is formed like a platform on the base plate 42 ina “V”-shape in plan view. More specifically, a plurality of holdinggrooves 48 a is formed in the contact piece holding part 48 so as tohave the same depth and the same shape and the base end sides of theleaf contact pieces 711, 712, 721, 722, 723, 731 and 732 are fitted intoand fixed to the holding grooves 48 a. In this embodiment, since all thedepths of the plurality of holding grooves 48 a are the same, the leafcontact pieces 711, 712, 721, 722, 723, 731 and 732 are held on the baseplate 42 at the same height positions.

In accordance with an embodiment, the tip end parts 721 c and 722 c ofthe leaf contact pieces 721 and 722 and the tip end part 723 c of theleaf contact piece 723 are abutted with the side faces of the cam parts558 and 559 of the rotary cam body 55 whose height positions from thebase plate 42 are different from each other. Therefore, in thisembodiment, as described with reference to FIG. 8(B), the leaf contactpiece 723 is straightly and horizontally extended from its base end sideand then perpendicularly turned upward and, after that, the leaf contactpiece 723 is extended horizontally again. On the other hand, the leafcontact pieces 721 and 222 are formed in a shape such that their baseend portions are straightly extended at the same height position as thatof the base end portion of the leaf contact piece 723 and the widths ofthe tip end parts 721 c and 722 c are enlarged upward. Therefore, evenwhen the base end sides of the leaf contact pieces 721, 722 and 723 areheld at the same height positions on the base plate 42, the tip endparts 721 c, 722 c and 723 c of the leaf contact pieces 721, 722 and 723can be preferably abutted with the side faces of the cam parts 558 and559 of the rotary cam body 55 whose height positions from the base plate42 are different from each other.

Further, in this embodiment, a circuit board 70 which is disposed toface the base plate 42 is superposed on the base end sides of the leafcontact pieces 711, 712, 721, 722, 723, 731 and 732. The circuit board70 is a PWB (Printed Wiring Board) provided with lands to which terminalparts 711 e, 712 e, 721 e, 722 e, 723 e, 731 e and 732 e formed uprighton the base end sides of the leaf contact pieces 711, 712, 721, 722,723, 731 and 732 are soldered. The circuit board 70 is provided with ahigh rigidity. In addition, the base plate 42 is covered by the outercase 43 shown in FIG. 12. The inner bottom face of the outer case 43 isformed with a rib 432 corresponding to an outer shape of the contactpiece holding part 48. Therefore, in a state that the inner case 41, thebase plate 42 and the outer case 43 are superposed to structure the casebody 4, the base end sides of the leaf contact pieces 711, 712, 721,722, 723, 731 and 732 are pressed in the widthwise direction, i.e.,toward the base plate 42 by the circuit board 70.

In this embodiment as described above, when the leaf contact pieces 711,712, 721, 722, 723, 731 and 732 are to be mounted on the base plate 42,the base end sides of the leaf contact pieces 711, 712, 721, 722, 723,731 and 732 are fitted into the holding grooves 48 a. As a result, theleaf contact pieces 711, 712, 721, 722, 723, 731 and 732 are mounted onthe base plate 42 with a high degree of positional accuracy so as to setin a prescribed direction at a predetermined height position and thus asuperior workability can be obtained. Further, it is not required toperform positional adjustment after the leaf contact pieces 711, 712,721, 722, 723, 731 and 732 have been mounted on the base plate 42.

Further, the leaf contact pieces 711, 712, 721, 722, 723, 731 and 732are pressed by the rib 432 of the outer case 43 through the circuitboard 70. Therefore, positional displacement of the leaf contact piecefrom its initial position or disengagement of the leaf contact piecefrom the holding groove 48 a does not occur. Further, the circuit board70 is provided with a high rigidity, which is different from a case thata flexible circuit board is used. Therefore, the leaf contact pieces711, 712, 721, 722, 723, 731 and 732 are surely fixed by the circuitboard 70.

In addition, the circuit board 70 is a single-side circuit board andthus wiring patterns are not formed on its under face. Therefore,insulation to the leaf contact pieces 711, 712, 721, 722, 723, 731 and732 can be surely secured.

In addition, in a case that the leaf contact pieces 711, 712, 721, 722,723, 731 and 732 are directly pressed by the outer case 43, a metalouter case 43 cannot be used and, moreover, the outer case 43 isrequired to have a high degree of rigidity and a high degree ofresistance against electricity. Therefore, material of the outer case 43is restricted. However, according to the embodiment of the presentinvention, the leaf contact pieces 711, 712, 721, 722, 723, 731 and 732are pressed through the circuit board 70 and thus restriction inmaterial of the outer case 43 can be prevented.

In the ice making device 1 in accordance with the embodiment, coolingfor making ice pieces in the ice tray 21 and heating for raking the icepieces are performed. The cooling and heating cause the inside of thecase body 4 to occur a rapid temperature change, which may cause dewformation. Further, in a refrigerator or a freezer which is providedwith the ice making device 1, when a door is opened and closed, atemperature change occurs to cause dew formation. Therefore, in the icemaking device 1 in accordance with an embodiment, a following dewformation countermeasure is adopted.

In other words, in the ice making device 1 in accordance with theembodiment, as shown in FIG. 3(A), the motor 5, the transmissionmechanism 50, the lever drive mechanism 65, the thermostat 91 and thelike are disposed in the first space 46 which is structured with theinner case 41 and the base plate 42. On the other hand, the upper halfportion of the rotary cam body 55 (cam face for the leaf switches), theice detecting switch 71, the main switch 72, the water-supply switch 73,the circuit board 70 and the like are disposed in the second space 47which is structured with the outer case 43 and the base plate 42.Further, the base plate 42 is formed with the through hole 421. However,the large diameter part 553 formed in a cylindrical shape of the rotarycam body 55 is fitted to the through hole 421 and thus a space formedwith the through hole 421 is substantially closed. The base plate 42 isformed with slits 425 but flat plate-shaped terminals 5 b (power supplymember) which are extended toward the outer case 43 from the upper faceof the motor 5 are fitted in the slits 425. Therefore, the first space46 and the second space 47 are substantially separated form each otherby the base plate 42. Accordingly, even when the ice tray 21 (ice makingunit 2) is abutted with a side face of the first space 46 (side face ofthe inner case 41), a rapid temperature variation is not occurred in thesecond space 47 and thus dew formation does not occur.

A bottom plate part of the outer case 43 shown in FIG. 12 is formed witha rib 431 (second partition wall) whose height is slightly lower thanthat of the outer wall 435. Therefore, when the base plate 42 and theouter case 43 are superposed on each other, the inside of the secondspace 47 is further partitioned into two spaces (first inner side smallspace 471 and second outer side small space 472) and the first innerside small space 471 is separated from a surrounding portion by the rib431 and the outer wall 435. Further, the rib 431 includes a facingportion 431 a which faces the outer wall 435 of the outer case 43 todoubly surround the first inner side small space 471.

In accordance with this embodiment, the upper half portion of the rotarycam body 55, the ice detecting switch 71, the main switch 72, thewater-supply switch 73, the circuit board 70 and the like are disposedin the first inner side small space 471 and, on the contrary, the inputlever 790 whose operation part 793 is required to be extended outsideand the like are disposed in the second outer side small space 472. Inaddition, when the ice tray 21 is abutted with the side face of theinner case 41, the ice tray 21 is located at a position corresponding tothe side of the second outer side small space 472 and the first innerside small space 471 is located at a position corresponding to a portionapart from the ice tray 21 (heater 26) than the second outer side smallspace 472. Accordingly, dew formation in the first inner side smallspace 471 in the inside of the second space 47, where the ice detectingswitch 71, the main switch 72, the water-supply switch 73, the circuitboard 70 and the like are disposed, can be surely prevented.

In accordance with the embodiment as described above, above-mentioneddouble dew formation countermeasures are provided in the first innersmall space 471 where the ice detecting switch 71, the main switch 72,the water-supply switch 73 and the circuit board 70 are disposed.Therefore, even when variation of temperature occurs outside, dew is notformed in the first inner side small space 471 and thus malfunction dueto freezing does not occur even when an inexpensive leaf switch is usedfor the ice detecting switch 71, the main switch 72 and the water-supplyswitch 73.

While the description above refers to particular embodiments of thepresent invention, it will be understood that many modifications may bemade without departing from the spirit thereof. The accompanying claimsare intended to cover such modifications as would fall within the truescope and spirit of the present invention.

The presently disclosed embodiments are therefore to be considered inall respects as illustrative and not restrictive, the scope of theinvention being indicated by the appended claims, rather than theforegoing description, and all changes which come within the meaning andrange of equivalency of the claims are therefore intended to be embracedtherein.

1. An ice making device comprising: an ice making unit having an icetray and a heater for heating the ice tray; and a drive unit which isconnected with the ice making unit and which comprises; a drive source;a cam body which is driven by the drive source; a leaf switch in which aleaf contact piece is displaced by a cam face of the cam body to perform“ON” or “OFF” operations; and a case body which accommodates the drivesource; wherein the cam body and the leaf switch are located in aninside of the case body; and wherein the case body is provided with afirst partition wall which partitions the inside of the case body into afirst space and a second space, and the leaf switch and at least the camface of the cam body is disposed in the second space.
 2. The ice makingdevice according to claim 1, wherein the first space is located on anice making unit side and the first space is interposed between thesecond space and the ice making unit.
 3. The ice making device accordingto claim 2, wherein the case body includes a base plate as the firstpartition wall which is disposed within the case body; one side portionof the cam body which is driven by a motor as the drive source isdisposed in the first space; the other side portion of the cam body isprotruded in the second space through a through hole which is formed inthe base plate; the one side portion of the cam body is formed with anouter teeth gear which is rotationally driven by the motor and acylindrical part for rotating a raking member for raking out ice piecesmanufactured in the ice tray of the ice making unit; and the other sideportion of the cam body disposed in the second space is formed with thecam face for performing “ON” and “OFF” operations with the leaf switch.4. The ice making device according to claim 3, wherein the rotary cambody is rotatably fitted into the through hole so as to close thethrough hole so that the first space and the second space arepartitioned off each other.
 5. The ice making device according to claim2, further comprising a second partition wall which is formed in thecase body for partitioning the second space into a first small space anda second small space; wherein the leaf switch and at least the cam faceof the cam body is disposed in the first small space.
 6. The ice makingdevice according to claim 5, wherein the first small space is formed ata position apart from the heater in comparison with the second smallspace.
 7. The ice making device according to claim 6, wherein the icetray and the heater for heating the ice tray are disposed on a side ofthe second small space.
 8. The ice making device according to claim 5,wherein the second partition wall includes a facing portion which facesan outer wall of the case body to doubly surround the first small space.9. The ice making device according to claim 1, wherein the drive sourceis disposed in the first space, and a power supply member for the drivesource is penetrated through a slit which is formed in the firstpartition wall.
 10. The ice making device according to claim 1, whereinthe drive source and a transmission mechanism for transmitting a drivingforce of the drive source to the ice making unit at a time ofdischarging ice pieces from the ice tray is disposed in the first space.